I read somewhere that the Velvet Underground were the first alternative band.

I don't remember the term "alternative" being applied to bands back then, but maybe "underground" had a similar meaning.

Music-wise, I'd say that if the Velvet Underground were alternative, then Bob was alternative before they were.

Before the early '60s, the alternatives to the top-40 were classical, jazz, or your parents music (swing, blues, ...).

Maybe Woody Guthrie was alternative.

The earliest act I've thought of that I can identify as alternative is probably the immortal Le Petomane.

Any earlier?